Postfix not honoring email aliases for local delivery

I have a hosting server, configured as per the Perfect Setup (Opensuse 10), with ISPConfig installed. Everything seems to be working - uptime has been over a month, now, with the only problems I've had so far being domain registration hiccups which have nothing to do with my server.

However, one of my customers is testing a web order form, and I've run into a problem: while emails incoming from outside servers work fine, local deliveries don't seem to be using email aliases properly.

If I send an email to [email protected] from outside, it works without a problem. If I send it from an another domain also hosted on the site, [email protected], it bounces back with the following error:

This is the Postfix program at host main.example.com. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to <postmaster> If you do so, please include this problem report. You can delete your own text from the attached returned message. The Postfix program <[email protected]>: unknown user: "info"

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I checked all the threads on Postfix problems I could, and the following have already been ruled out:

- The server's FQDN is main.example.com
- The $myhostname parameter in main.cf is main.example.com
- main.example.com is not used as a virtual domain for any email or web services. www.example.com and example.com are, however.
- All DNS entries are correct. Again, outside email works fine with the alias rewriting.
- alias_maps = hash:/etc/aliases
- virtual_maps = hash:/etc/postfix/virtusertable
- mydestination = /etc/postfix/local-host-names
- [email protected] and [email protected] are both present in /etc/postfix/virtusertable and point to example.admin
- example.com is listed in /etc/postfix/local-host-names

In this case, so I wasn't cluttering anyone else's mailbox, I set up the username testing, which has [email protected] as an alias, just so I could confirm the behaviour with a fresh email. (The original user who noticed the problem is on another site I host.) The user testing then forwards to [email protected].

The original notice was when a PHP script mailed to an alias - I got the undeliverable message error, since wwwrun's email forwards to me. I also tried sending to [email protected], with the same result (info is an alias for markanthony).

Beats me, too. The best I can figure out is that for local deliveries, ie between two email addresses on the same system, postfix isn't consulting the virtusertable at all, but just /etc/aliases, which of course doesn't include any of the aliases specified by ISPConfig. And I can't figure out a way to force it.

Sorry, I should also note that this is a big problem for me. I've got several sites with an [email protected] address, which is used by online ordering forms for the site in question. I can get the sites to change that, and create [email protected] addresses (which won't collide in local delivery) and get the PHP programmers to use that, but it seems clumsy and hackish, and means one more thing to spell out for programmers doing work for any of my sites.

My problem seems to be similar to the one in this thread. He's using opensuse 10.2, the same as me. And I've confirmed this behaviour with multiple accounts. If there is an entry in /etc/aliases for the username portion of the email address (i.e. a system username, not an alias set up in ISPConfig), then the mail is delivered. If the recipient is only in virtusertable, then email originating on another server is processed fine, but if the origin and destination are both hosted on my server, it will fail.

Maybe there's something missing from the default configuration of opensuse 10.2's postfix package? Do your servers have an entry for fallback_transport (or something related) in /etc/postfix/main.cf?